Did you do some research first?
Did you read the install guide ?
with win7 pre installed there is a "recovery" partition
that rhel ( it is not free by the way )
might have installed grub on
very common and VERY well documented
-- google it --- search : "dual boot windows 7" +RHEL
HOW did you install 5 ??
also why not the current RHEL6.1
seeing as YOU MUST buy a license for it RHEL is not free
why 5 and not the current 6
dose windows still install ?